>, the SanDisk Extreme 30MB/s took 9 seconds and the new 45MB/s UHS-1 >card took 7 seconds to totally clear the buffer. > >Since it takes only about 1.5 seconds to take the 10 shots >that fill the buffer in the camera a card that could keep up >with that data rate would need to have a data transfer rate of >about 90MB/s. And this assumes the internal >processing/buffer/write system could deliver data at that >rate. In fact a card like that would minimize the need for a >large internal buffer. >
Thanks again Dean! This time you are saving me money
For the 9 second to 7 second difference I won't rush out just yet and get a UHS-1 card. I know the CF top of the line cards already achieve 90 Mbps so maybe we aren't too far away in the SD format. IIRC even Panasonic (and other) were supposed to announce some 75 Mbps SD cards but I don't recall seeing them released to market.
I am dreaming of a day when we can do what you indicate in your last sentence. No need for a large buffer on the camera if the throughput to the card is fast enough. It will be interesting to see if the buffer emptying can be dropped from the 7 second level with yet a faster card or whether in fact that is now the limit of the speed the camera can do. I think I read somewhere else the 45Mbps cards may now be at the limit of the buffer emptying capacity of the camera, but I prefer your tests as they are clear and concise.
The D7K buffer is comparatively miserly as compared to higher in the Nikon camera food-chain so we have to be pretty careful with our bursts. That is one thing I notice when I still occasionally use my D300, it hammers away merrily in comparison on long bursts.